//
//  httplib.h
//
//  Copyright (c) 2019 Yuji Hirose. All rights reserved.
//  MIT License
//

#ifndef CPPHTTPLIB_HTTPLIB_H
#define CPPHTTPLIB_HTTPLIB_H

#ifdef _WIN32
#ifndef _CRT_SECURE_NO_WARNINGS
#define _CRT_SECURE_NO_WARNINGS
#endif //_CRT_SECURE_NO_WARNINGS

#ifndef _CRT_NONSTDC_NO_DEPRECATE
#define _CRT_NONSTDC_NO_DEPRECATE
#endif //_CRT_NONSTDC_NO_DEPRECATE

#if defined(_MSC_VER) && _MSC_VER < 1900
#define snprintf _snprintf_s
#endif // _MSC_VER

#ifndef S_ISREG
#define S_ISREG(m) (((m)&S_IFREG) == S_IFREG)
#endif // S_ISREG

#ifndef S_ISDIR
#define S_ISDIR(m) (((m)&S_IFDIR) == S_IFDIR)
#endif // S_ISDIR

#ifndef NOMINMAX
#define NOMINMAX
#endif // NOMINMAX

#include <io.h>
#include <winsock2.h>
#include <ws2tcpip.h>

#pragma comment(lib, "ws2_32.lib")

#ifndef strcasecmp
#define strcasecmp _stricmp
#endif // strcasecmp

typedef SOCKET socket_t;
#else
#include <arpa/inet.h>
#include <cstring>
#include <netdb.h>
#include <netinet/in.h>
#include <pthread.h>
#include <signal.h>
#include <sys/select.h>
#include <sys/socket.h>
#include <unistd.h>

typedef int socket_t;
#define INVALID_SOCKET (-1)
#endif //_WIN32

#include <assert.h>
#include <fcntl.h>
#include <fstream>
#include <functional>
#include <map>
#include <memory>
#include <mutex>
#include <regex>
#include <string>
#include <sys/stat.h>
#include <thread>

#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
#include <openssl/err.h>
#include <openssl/ssl.h>
#endif

#ifdef CPPHTTPLIB_ZLIB_SUPPORT
#include <zlib.h>
#endif

/*
 * Configuration
 */
#define CPPHTTPLIB_KEEPALIVE_TIMEOUT_SECOND 5
#define CPPHTTPLIB_KEEPALIVE_TIMEOUT_USECOND 0
#define CPPHTTPLIB_KEEPALIVE_MAX_COUNT 5
#define CPPHTTPLIB_REQUEST_URI_MAX_LENGTH 8192
#define CPPHTTPLIB_PAYLOAD_MAX_LENGTH std::numeric_limits<uint64_t>::max()

namespace httplib {

namespace detail {

struct ci {
  bool operator()(const std::string &s1, const std::string &s2) const {
    return std::lexicographical_compare(
        s1.begin(), s1.end(), s2.begin(), s2.end(),
        [](char c1, char c2) { return ::tolower(c1) < ::tolower(c2); });
  }
};

} // namespace detail

enum class HttpVersion { v1_0 = 0, v1_1 };

typedef std::multimap<std::string, std::string, detail::ci> Headers;

template <typename uint64_t, typename... Args>
std::pair<std::string, std::string> make_range_header(uint64_t value,
                                                      Args... args);

typedef std::multimap<std::string, std::string> Params;
typedef std::smatch Match;
typedef std::function<bool(uint64_t current, uint64_t total)> Progress;

struct MultipartFile {
  std::string filename;
  std::string content_type;
  size_t offset = 0;
  size_t length = 0;
};
typedef std::multimap<std::string, MultipartFile> MultipartFiles;

struct Request {
  std::string version;
  std::string method;
  std::string target;
  std::string path;
  Headers headers;
  std::string body;
  Params params;
  MultipartFiles files;
  Match matches;

  Progress progress;

  bool has_header(const char *key) const;
  std::string get_header_value(const char *key, size_t id = 0) const;
  size_t get_header_value_count(const char *key) const;
  void set_header(const char *key, const char *val);

  bool has_param(const char *key) const;
  std::string get_param_value(const char *key, size_t id = 0) const;
  size_t get_param_value_count(const char *key) const;

  bool has_file(const char *key) const;
  MultipartFile get_file_value(const char *key) const;
};

struct Response {
  std::string version;
  int status;
  Headers headers;
  std::string body;
  std::function<std::string(uint64_t offset)> streamcb;

  bool has_header(const char *key) const;
  std::string get_header_value(const char *key, size_t id = 0) const;
  size_t get_header_value_count(const char *key) const;
  void set_header(const char *key, const char *val);

  void set_redirect(const char *uri);
  void set_content(const char *s, size_t n, const char *content_type);
  void set_content(const std::string &s, const char *content_type);

  Response() : status(-1) {}
};

class Stream {
public:
  virtual ~Stream() {}
  virtual int read(char *ptr, size_t size) = 0;
  virtual int write(const char *ptr, size_t size1) = 0;
  virtual int write(const char *ptr) = 0;
  virtual std::string get_remote_addr() const = 0;

  template <typename... Args>
  void write_format(const char *fmt, const Args &... args);
};

class SocketStream : public Stream {
public:
  SocketStream(socket_t sock);
  virtual ~SocketStream();

  virtual int read(char *ptr, size_t size);
  virtual int write(const char *ptr, size_t size);
  virtual int write(const char *ptr);
  virtual std::string get_remote_addr() const;

private:
  socket_t sock_;
};

class BufferStream : public Stream {
public:
  BufferStream() {}
  virtual ~BufferStream() {}

  virtual int read(char *ptr, size_t size);
  virtual int write(const char *ptr, size_t size);
  virtual int write(const char *ptr);
  virtual std::string get_remote_addr() const;

  const std::string &get_buffer() const;

private:
  std::string buffer;
};

class Server {
public:
  typedef std::function<void(const Request &, Response &)> Handler;
  typedef std::function<void(const Request &, const Response &)> Logger;

  Server();

  virtual ~Server();

  virtual bool is_valid() const;

  Server &Get(const char *pattern, Handler handler);
  Server &Post(const char *pattern, Handler handler);

  Server &Put(const char *pattern, Handler handler);
  Server &Patch(const char *pattern, Handler handler);
  Server &Delete(const char *pattern, Handler handler);
  Server &Options(const char *pattern, Handler handler);

  bool set_base_dir(const char *path);

  void set_error_handler(Handler handler);
  void set_logger(Logger logger);

  void set_keep_alive_max_count(size_t count);
  void set_payload_max_length(uint64_t length);

  int bind_to_any_port(const char *host, int socket_flags = 0);
  bool listen_after_bind();

  bool listen(const char *host, int port, int socket_flags = 0);

  bool is_running() const;
  void stop();

protected:
  bool process_request(Stream &strm, bool last_connection,
                       bool &connection_close);

  size_t keep_alive_max_count_;
  size_t payload_max_length_;

private:
  typedef std::vector<std::pair<std::regex, Handler>> Handlers;

  socket_t create_server_socket(const char *host, int port,
                                int socket_flags) const;
  int bind_internal(const char *host, int port, int socket_flags);
  bool listen_internal();

  bool routing(Request &req, Response &res);
  bool handle_file_request(Request &req, Response &res);
  bool dispatch_request(Request &req, Response &res, Handlers &handlers);

  bool parse_request_line(const char *s, Request &req);
  void write_response(Stream &strm, bool last_connection, const Request &req,
                      Response &res);

  virtual bool read_and_close_socket(socket_t sock);

  bool is_running_;
  socket_t svr_sock_;
  std::string base_dir_;
  Handlers get_handlers_;
  Handlers post_handlers_;
  Handlers put_handlers_;
  Handlers patch_handlers_;
  Handlers delete_handlers_;
  Handlers options_handlers_;
  Handler error_handler_;
  Logger logger_;

  // TODO: Use thread pool...
  std::mutex running_threads_mutex_;
  int running_threads_;
};

class Client {
public:
  Client(const char *host, int port = 80, time_t timeout_sec = 300);

  virtual ~Client();

  virtual bool is_valid() const;

  std::shared_ptr<Response> Get(const char *path, Progress progress = nullptr);
  std::shared_ptr<Response> Get(const char *path, const Headers &headers,
                                Progress progress = nullptr);

  std::shared_ptr<Response> Head(const char *path);
  std::shared_ptr<Response> Head(const char *path, const Headers &headers);

  std::shared_ptr<Response> Post(const char *path, const std::string &body,
                                 const char *content_type);
  std::shared_ptr<Response> Post(const char *path, const Headers &headers,
                                 const std::string &body,
                                 const char *content_type);

  std::shared_ptr<Response> Post(const char *path, const Params &params);
  std::shared_ptr<Response> Post(const char *path, const Headers &headers,
                                 const Params &params);

  std::shared_ptr<Response> Put(const char *path, const std::string &body,
                                const char *content_type);
  std::shared_ptr<Response> Put(const char *path, const Headers &headers,
                                const std::string &body,
                                const char *content_type);

  std::shared_ptr<Response> Patch(const char *path, const std::string &body,
                                  const char *content_type);
  std::shared_ptr<Response> Patch(const char *path, const Headers &headers,
                                  const std::string &body,
                                  const char *content_type);

  std::shared_ptr<Response> Delete(const char *path);
  std::shared_ptr<Response> Delete(const char *path, const Headers &headers);

  std::shared_ptr<Response> Options(const char *path);
  std::shared_ptr<Response> Options(const char *path, const Headers &headers);

  bool send(Request &req, Response &res);

protected:
  bool process_request(Stream &strm, Request &req, Response &res,
                       bool &connection_close);

  const std::string host_;
  const int port_;
  time_t timeout_sec_;
  const std::string host_and_port_;

private:
  socket_t create_client_socket() const;
  bool read_response_line(Stream &strm, Response &res);
  void write_request(Stream &strm, Request &req);

  virtual bool read_and_close_socket(socket_t sock, Request &req,
                                     Response &res);
  virtual bool is_ssl() const;
};

#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
class SSLSocketStream : public Stream {
public:
  SSLSocketStream(socket_t sock, SSL *ssl);
  virtual ~SSLSocketStream();

  virtual int read(char *ptr, size_t size);
  virtual int write(const char *ptr, size_t size);
  virtual int write(const char *ptr);
  virtual std::string get_remote_addr() const;

private:
  socket_t sock_;
  SSL *ssl_;
};

class SSLServer : public Server {
public:
  SSLServer(const char *cert_path, const char *private_key_path);

  virtual ~SSLServer();

  virtual bool is_valid() const;

private:
  virtual bool read_and_close_socket(socket_t sock);

  SSL_CTX *ctx_;
  std::mutex ctx_mutex_;
};

class SSLClient : public Client {
public:
  SSLClient(const char *host, int port = 443, time_t timeout_sec = 300);

  virtual ~SSLClient();

  virtual bool is_valid() const;

private:
  virtual bool read_and_close_socket(socket_t sock, Request &req,
                                     Response &res);
  virtual bool is_ssl() const;

  SSL_CTX *ctx_;
  std::mutex ctx_mutex_;
};
#endif

/*
 * Implementation
 */
namespace detail {

template <class Fn> void split(const char *b, const char *e, char d, Fn fn) {
  int i = 0;
  int beg = 0;

  while (e ? (b + i != e) : (b[i] != '\0')) {
    if (b[i] == d) {
      fn(&b[beg], &b[i]);
      beg = i + 1;
    }
    i++;
  }

  if (i) { fn(&b[beg], &b[i]); }
}

// NOTE: until the read size reaches `fixed_buffer_size`, use `fixed_buffer`
// to store data. The call can set memory on stack for performance.
class stream_line_reader {
public:
  stream_line_reader(Stream &strm, char *fixed_buffer, size_t fixed_buffer_size)
      : strm_(strm), fixed_buffer_(fixed_buffer),
        fixed_buffer_size_(fixed_buffer_size) {}

  const char *ptr() const {
    if (glowable_buffer_.empty()) {
      return fixed_buffer_;
    } else {
      return glowable_buffer_.data();
    }
  }

  size_t size() const {
    if (glowable_buffer_.empty()) {
      return fixed_buffer_used_size_;
    } else {
      return glowable_buffer_.size();
    }
  }

  bool getline() {
    fixed_buffer_used_size_ = 0;
    glowable_buffer_.clear();

    for (size_t i = 0;; i++) {
      char byte;
      auto n = strm_.read(&byte, 1);

      if (n < 0) {
        return false;
      } else if (n == 0) {
        if (i == 0) {
          return false;
        } else {
          break;
        }
      }

      append(byte);

      if (byte == '\n') { break; }
    }

    return true;
  }

private:
  void append(char c) {
    if (fixed_buffer_used_size_ < fixed_buffer_size_ - 1) {
      fixed_buffer_[fixed_buffer_used_size_++] = c;
      fixed_buffer_[fixed_buffer_used_size_] = '\0';
    } else {
      if (glowable_buffer_.empty()) {
        assert(fixed_buffer_[fixed_buffer_used_size_] == '\0');
        glowable_buffer_.assign(fixed_buffer_, fixed_buffer_used_size_);
      }
      glowable_buffer_ += c;
    }
  }

  Stream &strm_;
  char *fixed_buffer_;
  const size_t fixed_buffer_size_;
  size_t fixed_buffer_used_size_;
  std::string glowable_buffer_;
};

inline int close_socket(socket_t sock) {
#ifdef _WIN32
  return closesocket(sock);
#else
  return close(sock);
#endif
}

inline int select_read(socket_t sock, time_t sec, time_t usec) {
  fd_set fds;
  FD_ZERO(&fds);
  FD_SET(sock, &fds);

  timeval tv;
  tv.tv_sec = static_cast<long>(sec);
  tv.tv_usec = static_cast<long>(usec);

  return select(static_cast<int>(sock + 1), &fds, NULL, NULL, &tv);
}

inline bool wait_until_socket_is_ready(socket_t sock, time_t sec, time_t usec) {
  fd_set fdsr;
  FD_ZERO(&fdsr);
  FD_SET(sock, &fdsr);

  auto fdsw = fdsr;
  auto fdse = fdsr;

  timeval tv;
  tv.tv_sec = static_cast<long>(sec);
  tv.tv_usec = static_cast<long>(usec);

  if (select(static_cast<int>(sock + 1), &fdsr, &fdsw, &fdse, &tv) < 0) {
    return false;
  } else if (FD_ISSET(sock, &fdsr) || FD_ISSET(sock, &fdsw)) {
    int error = 0;
    socklen_t len = sizeof(error);
    if (getsockopt(sock, SOL_SOCKET, SO_ERROR, (char *)&error, &len) < 0 ||
        error) {
      return false;
    }
  } else {
    return false;
  }

  return true;
}

template <typename T>
inline bool read_and_close_socket(socket_t sock, size_t keep_alive_max_count,
                                  T callback) {
  bool ret = false;

  if (keep_alive_max_count > 0) {
    auto count = keep_alive_max_count;
    while (count > 0 &&
           detail::select_read(sock, CPPHTTPLIB_KEEPALIVE_TIMEOUT_SECOND,
                               CPPHTTPLIB_KEEPALIVE_TIMEOUT_USECOND) > 0) {
      SocketStream strm(sock);
      auto last_connection = count == 1;
      auto connection_close = false;

      ret = callback(strm, last_connection, connection_close);
      if (!ret || connection_close) { break; }

      count--;
    }
  } else {
    SocketStream strm(sock);
    auto dummy_connection_close = false;
    ret = callback(strm, true, dummy_connection_close);
  }

  close_socket(sock);
  return ret;
}

inline int shutdown_socket(socket_t sock) {
#ifdef _WIN32
  return shutdown(sock, SD_BOTH);
#else
  return shutdown(sock, SHUT_RDWR);
#endif
}

template <typename Fn>
socket_t create_socket(const char *host, int port, Fn fn,
                       int socket_flags = 0) {
#ifdef _WIN32
#define SO_SYNCHRONOUS_NONALERT 0x20
#define SO_OPENTYPE 0x7008

  int opt = SO_SYNCHRONOUS_NONALERT;
  setsockopt(INVALID_SOCKET, SOL_SOCKET, SO_OPENTYPE, (char *)&opt,
             sizeof(opt));
#endif

  // Get address info
  struct addrinfo hints;
  struct addrinfo *result;

  memset(&hints, 0, sizeof(struct addrinfo));
  hints.ai_family = AF_UNSPEC;
  hints.ai_socktype = SOCK_STREAM;
  hints.ai_flags = socket_flags;
  hints.ai_protocol = 0;

  auto service = std::to_string(port);

  if (getaddrinfo(host, service.c_str(), &hints, &result)) {
    return INVALID_SOCKET;
  }

  for (auto rp = result; rp; rp = rp->ai_next) {
    // Create a socket
    auto sock = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
    if (sock == INVALID_SOCKET) { continue; }

    // Make 'reuse address' option available
    int yes = 1;
    setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (char *)&yes, sizeof(yes));

    // bind or connect
    if (fn(sock, *rp)) {
      freeaddrinfo(result);
      return sock;
    }

    close_socket(sock);
  }

  freeaddrinfo(result);
  return INVALID_SOCKET;
}

inline void set_nonblocking(socket_t sock, bool nonblocking) {
#ifdef _WIN32
  auto flags = nonblocking ? 1UL : 0UL;
  ioctlsocket(sock, FIONBIO, &flags);
#else
  auto flags = fcntl(sock, F_GETFL, 0);
  fcntl(sock, F_SETFL,
        nonblocking ? (flags | O_NONBLOCK) : (flags & (~O_NONBLOCK)));
#endif
}

inline bool is_connection_error() {
#ifdef _WIN32
  return WSAGetLastError() != WSAEWOULDBLOCK;
#else
  return errno != EINPROGRESS;
#endif
}

inline std::string get_remote_addr(socket_t sock) {
  struct sockaddr_storage addr;
  socklen_t len = sizeof(addr);

  if (!getpeername(sock, (struct sockaddr *)&addr, &len)) {
    char ipstr[NI_MAXHOST];

    if (!getnameinfo((struct sockaddr *)&addr, len, ipstr, sizeof(ipstr),
                     nullptr, 0, NI_NUMERICHOST)) {
      return ipstr;
    }
  }

  return std::string();
}

inline bool is_file(const std::string &path) {
  struct stat st;
  return stat(path.c_str(), &st) >= 0 && S_ISREG(st.st_mode);
}

inline bool is_dir(const std::string &path) {
  struct stat st;
  return stat(path.c_str(), &st) >= 0 && S_ISDIR(st.st_mode);
}

inline bool is_valid_path(const std::string &path) {
  size_t level = 0;
  size_t i = 0;

  // Skip slash
  while (i < path.size() && path[i] == '/') {
    i++;
  }

  while (i < path.size()) {
    // Read component
    auto beg = i;
    while (i < path.size() && path[i] != '/') {
      i++;
    }

    auto len = i - beg;
    assert(len > 0);

    if (!path.compare(beg, len, ".")) {
      ;
    } else if (!path.compare(beg, len, "..")) {
      if (level == 0) { return false; }
      level--;
    } else {
      level++;
    }

    // Skip slash
    while (i < path.size() && path[i] == '/') {
      i++;
    }
  }

  return true;
}

inline void read_file(const std::string &path, std::string &out) {
  std::ifstream fs(path, std::ios_base::binary);
  fs.seekg(0, std::ios_base::end);
  auto size = fs.tellg();
  fs.seekg(0);
  out.resize(static_cast<size_t>(size));
  fs.read(&out[0], size);
}

inline std::string file_extension(const std::string &path) {
  std::smatch m;
  auto pat = std::regex("\\.([a-zA-Z0-9]+)$");
  if (std::regex_search(path, m, pat)) { return m[1].str(); }
  return std::string();
}

inline const char *find_content_type(const std::string &path) {
  auto ext = file_extension(path);
  if (ext == "txt") {
    return "text/plain";
  } else if (ext == "html") {
    return "text/html";
  } else if (ext == "css") {
    return "text/css";
  } else if (ext == "jpeg" || ext == "jpg") {
    return "image/jpg";
  } else if (ext == "png") {
    return "image/png";
  } else if (ext == "gif") {
    return "image/gif";
  } else if (ext == "svg") {
    return "image/svg+xml";
  } else if (ext == "ico") {
    return "image/x-icon";
  } else if (ext == "json") {
    return "application/json";
  } else if (ext == "pdf") {
    return "application/pdf";
  } else if (ext == "js") {
    return "application/javascript";
  } else if (ext == "xml") {
    return "application/xml";
  } else if (ext == "xhtml") {
    return "application/xhtml+xml";
  }
  return nullptr;
}

inline const char *status_message(int status) {
  switch (status) {
  case 200: return "OK";
  case 301: return "Moved Permanently";
  case 302: return "Found";
  case 303: return "See Other";
  case 304: return "Not Modified";
  case 400: return "Bad Request";
  case 403: return "Forbidden";
  case 404: return "Not Found";
  case 413: return "Payload Too Large";
  case 414: return "Request-URI Too Long";
  case 415: return "Unsupported Media Type";
  default:
  case 500: return "Internal Server Error";
  }
}

inline bool has_header(const Headers &headers, const char *key) {
  return headers.find(key) != headers.end();
}

inline const char *get_header_value(const Headers &headers, const char *key,
                                    size_t id = 0, const char *def = nullptr) {
  auto it = headers.find(key);
  std::advance(it, id);
  if (it != headers.end()) { return it->second.c_str(); }
  return def;
}

inline uint64_t get_header_value_uint64(const Headers &headers, const char *key,
                                        int def = 0) {
  auto it = headers.find(key);
  if (it != headers.end()) {
    return std::strtoull(it->second.data(), nullptr, 10);
  }
  return def;
}

inline bool read_headers(Stream &strm, Headers &headers) {
  static std::regex re(R"((.+?):\s*(.+?)\s*\r\n)");

  const auto bufsiz = 2048;
  char buf[bufsiz];

  stream_line_reader reader(strm, buf, bufsiz);

  for (;;) {
    if (!reader.getline()) { return false; }
    if (!strcmp(reader.ptr(), "\r\n")) { break; }
    std::cmatch m;
    if (std::regex_match(reader.ptr(), m, re)) {
      auto key = std::string(m[1]);
      auto val = std::string(m[2]);
      headers.emplace(key, val);
    }
  }

  return true;
}

inline bool read_content_with_length(Stream &strm, std::string &out, size_t len,
                                     Progress progress) {
  out.assign(len, 0);
  size_t r = 0;
  while (r < len) {
    auto n = strm.read(&out[r], len - r);
    if (n <= 0) { return false; }

    r += n;

    if (progress) {
      if (!progress(r, len)) { return false; }
    }
  }

  return true;
}

inline bool read_content_without_length(Stream &strm, std::string &out) {
  for (;;) {
    char byte;
    auto n = strm.read(&byte, 1);
    if (n < 0) {
      return false;
    } else if (n == 0) {
      return true;
    }
    out += byte;
  }

  return true;
}

inline bool read_content_chunked(Stream &strm, std::string &out) {
  const auto bufsiz = 16;
  char buf[bufsiz];

  stream_line_reader reader(strm, buf, bufsiz);

  if (!reader.getline()) { return false; }

  auto chunk_len = std::stoi(reader.ptr(), 0, 16);

  while (chunk_len > 0) {
    std::string chunk;
    if (!read_content_with_length(strm, chunk, chunk_len, nullptr)) {
      return false;
    }

    if (!reader.getline()) { return false; }

    if (strcmp(reader.ptr(), "\r\n")) { break; }

    out += chunk;

    if (!reader.getline()) { return false; }

    chunk_len = std::stoi(reader.ptr(), 0, 16);
  }

  if (chunk_len == 0) {
    // Reader terminator after chunks
    if (!reader.getline() || strcmp(reader.ptr(), "\r\n")) return false;
  }

  return true;
}

template <typename T>
bool read_content(Stream &strm, T &x, uint64_t payload_max_length,
                  bool &exceed_payload_max_length,
                  Progress progress = Progress()) {
  if (has_header(x.headers, "Content-Length")) {
    auto len = get_header_value_uint64(x.headers, "Content-Length", 0);
    if (len == 0) {
      const auto &encoding =
          get_header_value(x.headers, "Transfer-Encoding", 0, "");
      if (!strcasecmp(encoding, "chunked")) {
        return read_content_chunked(strm, x.body);
      }
    }

    if ((len > payload_max_length) ||
        // For 32-bit platform
        (sizeof(size_t) < sizeof(uint64_t) &&
         len > std::numeric_limits<size_t>::max())) {
      exceed_payload_max_length = true;
      return false;
    }

    return read_content_with_length(strm, x.body, len, progress);
  } else {
    const auto &encoding =
        get_header_value(x.headers, "Transfer-Encoding", 0, "");
    if (!strcasecmp(encoding, "chunked")) {
      return read_content_chunked(strm, x.body);
    }
    return read_content_without_length(strm, x.body);
  }
  return true;
}

template <typename T> inline void write_headers(Stream &strm, const T &info) {
  for (const auto &x : info.headers) {
    strm.write_format("%s: %s\r\n", x.first.c_str(), x.second.c_str());
  }
  strm.write("\r\n");
}

inline std::string encode_url(const std::string &s) {
  std::string result;

  for (auto i = 0; s[i]; i++) {
    switch (s[i]) {
    case ' ': result += "%20"; break;
    case '+': result += "%2B"; break;
    case '\r': result += "%0D"; break;
    case '\n': result += "%0A"; break;
    case '\'': result += "%27"; break;
    case ',': result += "%2C"; break;
    case ':': result += "%3A"; break;
    case ';': result += "%3B"; break;
    default:
      auto c = static_cast<uint8_t>(s[i]);
      if (c >= 0x80) {
        result += '%';
        char hex[4];
        size_t len = snprintf(hex, sizeof(hex) - 1, "%02X", c);
        assert(len == 2);
        result.append(hex, len);
      } else {
        result += s[i];
      }
      break;
    }
  }

  return result;
}

inline bool is_hex(char c, int &v) {
  if (0x20 <= c && isdigit(c)) {
    v = c - '0';
    return true;
  } else if ('A' <= c && c <= 'F') {
    v = c - 'A' + 10;
    return true;
  } else if ('a' <= c && c <= 'f') {
    v = c - 'a' + 10;
    return true;
  }
  return false;
}

inline bool from_hex_to_i(const std::string &s, size_t i, size_t cnt,
                          int &val) {
  if (i >= s.size()) { return false; }

  val = 0;
  for (; cnt; i++, cnt--) {
    if (!s[i]) { return false; }
    int v = 0;
    if (is_hex(s[i], v)) {
      val = val * 16 + v;
    } else {
      return false;
    }
  }
  return true;
}

inline std::string from_i_to_hex(uint64_t n) {
  const char *charset = "0123456789abcdef";
  std::string ret;
  do {
    ret = charset[n & 15] + ret;
    n >>= 4;
  } while (n > 0);
  return ret;
}

inline size_t to_utf8(int code, char *buff) {
  if (code < 0x0080) {
    buff[0] = (code & 0x7F);
    return 1;
  } else if (code < 0x0800) {
    buff[0] = (0xC0 | ((code >> 6) & 0x1F));
    buff[1] = (0x80 | (code & 0x3F));
    return 2;
  } else if (code < 0xD800) {
    buff[0] = (0xE0 | ((code >> 12) & 0xF));
    buff[1] = (0x80 | ((code >> 6) & 0x3F));
    buff[2] = (0x80 | (code & 0x3F));
    return 3;
  } else if (code < 0xE000) { // D800 - DFFF is invalid...
    return 0;
  } else if (code < 0x10000) {
    buff[0] = (0xE0 | ((code >> 12) & 0xF));
    buff[1] = (0x80 | ((code >> 6) & 0x3F));
    buff[2] = (0x80 | (code & 0x3F));
    return 3;
  } else if (code < 0x110000) {
    buff[0] = (0xF0 | ((code >> 18) & 0x7));
    buff[1] = (0x80 | ((code >> 12) & 0x3F));
    buff[2] = (0x80 | ((code >> 6) & 0x3F));
    buff[3] = (0x80 | (code & 0x3F));
    return 4;
  }

  // NOTREACHED
  return 0;
}

inline std::string decode_url(const std::string &s) {
  std::string result;

  for (size_t i = 0; i < s.size(); i++) {
    if (s[i] == '%' && i + 1 < s.size()) {
      if (s[i + 1] == 'u') {
        int val = 0;
        if (from_hex_to_i(s, i + 2, 4, val)) {
          // 4 digits Unicode codes
          char buff[4];
          size_t len = to_utf8(val, buff);
          if (len > 0) { result.append(buff, len); }
          i += 5; // 'u0000'
        } else {
          result += s[i];
        }
      } else {
        int val = 0;
        if (from_hex_to_i(s, i + 1, 2, val)) {
          // 2 digits hex codes
          result += val;
          i += 2; // '00'
        } else {
          result += s[i];
        }
      }
    } else if (s[i] == '+') {
      result += ' ';
    } else {
      result += s[i];
    }
  }

  return result;
}

inline void parse_query_text(const std::string &s, Params &params) {
  split(&s[0], &s[s.size()], '&', [&](const char *b, const char *e) {
    std::string key;
    std::string val;
    split(b, e, '=', [&](const char *b, const char *e) {
      if (key.empty()) {
        key.assign(b, e);
      } else {
        val.assign(b, e);
      }
    });
    params.emplace(key, decode_url(val));
  });
}

inline bool parse_multipart_boundary(const std::string &content_type,
                                     std::string &boundary) {
  auto pos = content_type.find("boundary=");
  if (pos == std::string::npos) { return false; }

  boundary = content_type.substr(pos + 9);
  return true;
}

inline bool parse_multipart_formdata(const std::string &boundary,
                                     const std::string &body,
                                     MultipartFiles &files) {
  static std::string dash = "--";
  static std::string crlf = "\r\n";

  static std::regex re_content_type("Content-Type: (.*?)",
                                    std::regex_constants::icase);

  static std::regex re_content_disposition(
      "Content-Disposition: form-data; name=\"(.*?)\"(?:; filename=\"(.*?)\")?",
      std::regex_constants::icase);

  auto dash_boundary = dash + boundary;

  auto pos = body.find(dash_boundary);
  if (pos != 0) { return false; }

  pos += dash_boundary.size();

  auto next_pos = body.find(crlf, pos);
  if (next_pos == std::string::npos) { return false; }

  pos = next_pos + crlf.size();

  while (pos < body.size()) {
    next_pos = body.find(crlf, pos);
    if (next_pos == std::string::npos) { return false; }

    std::string name;
    MultipartFile file;

    auto header = body.substr(pos, (next_pos - pos));

    while (pos != next_pos) {
      std::smatch m;
      if (std::regex_match(header, m, re_content_type)) {
        file.content_type = m[1];
      } else if (std::regex_match(header, m, re_content_disposition)) {
        name = m[1];
        file.filename = m[2];
      }

      pos = next_pos + crlf.size();

      next_pos = body.find(crlf, pos);
      if (next_pos == std::string::npos) { return false; }

      header = body.substr(pos, (next_pos - pos));
    }

    pos = next_pos + crlf.size();

    next_pos = body.find(crlf + dash_boundary, pos);

    if (next_pos == std::string::npos) { return false; }

    file.offset = pos;
    file.length = next_pos - pos;

    pos = next_pos + crlf.size() + dash_boundary.size();

    next_pos = body.find(crlf, pos);
    if (next_pos == std::string::npos) { return false; }

    files.emplace(name, file);

    pos = next_pos + crlf.size();
  }

  return true;
}

inline std::string to_lower(const char *beg, const char *end) {
  std::string out;
  auto it = beg;
  while (it != end) {
    out += ::tolower(*it);
    it++;
  }
  return out;
}

inline void make_range_header_core(std::string &) {}

template <typename uint64_t>
inline void make_range_header_core(std::string &field, uint64_t value) {
  if (!field.empty()) { field += ", "; }
  field += std::to_string(value) + "-";
}

template <typename uint64_t, typename... Args>
inline void make_range_header_core(std::string &field, uint64_t value1,
                                   uint64_t value2, Args... args) {
  if (!field.empty()) { field += ", "; }
  field += std::to_string(value1) + "-" + std::to_string(value2);
  make_range_header_core(field, args...);
}

#ifdef CPPHTTPLIB_ZLIB_SUPPORT
inline bool can_compress(const std::string &content_type) {
  return !content_type.find("text/") || content_type == "image/svg+xml" ||
         content_type == "application/javascript" ||
         content_type == "application/json" ||
         content_type == "application/xml" ||
         content_type == "application/xhtml+xml";
}

inline void compress(std::string &content) {
  z_stream strm;
  strm.zalloc = Z_NULL;
  strm.zfree = Z_NULL;
  strm.opaque = Z_NULL;

  auto ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, Z_DEFLATED, 31, 8,
                          Z_DEFAULT_STRATEGY);
  if (ret != Z_OK) { return; }

  strm.avail_in = content.size();
  strm.next_in = (Bytef *)content.data();

  std::string compressed;

  const auto bufsiz = 16384;
  char buff[bufsiz];
  do {
    strm.avail_out = bufsiz;
    strm.next_out = (Bytef *)buff;
    deflate(&strm, Z_FINISH);
    compressed.append(buff, bufsiz - strm.avail_out);
  } while (strm.avail_out == 0);

  content.swap(compressed);

  deflateEnd(&strm);
}

inline void decompress(std::string &content) {
  z_stream strm;
  strm.zalloc = Z_NULL;
  strm.zfree = Z_NULL;
  strm.opaque = Z_NULL;

  // 15 is the value of wbits, which should be at the maximum possible value to
  // ensure that any gzip stream can be decoded. The offset of 16 specifies that
  // the stream to decompress will be formatted with a gzip wrapper.
  auto ret = inflateInit2(&strm, 16 + 15);
  if (ret != Z_OK) { return; }

  strm.avail_in = content.size();
  strm.next_in = (Bytef *)content.data();

  std::string decompressed;

  const auto bufsiz = 16384;
  char buff[bufsiz];
  do {
    strm.avail_out = bufsiz;
    strm.next_out = (Bytef *)buff;
    inflate(&strm, Z_NO_FLUSH);
    decompressed.append(buff, bufsiz - strm.avail_out);
  } while (strm.avail_out == 0);

  content.swap(decompressed);

  inflateEnd(&strm);
}
#endif

#ifdef _WIN32
class WSInit {
public:
  WSInit() {
    WSADATA wsaData;
    WSAStartup(0x0002, &wsaData);
  }

  ~WSInit() { WSACleanup(); }
};

static WSInit wsinit_;
#endif

} // namespace detail

// Header utilities
template <typename uint64_t, typename... Args>
inline std::pair<std::string, std::string> make_range_header(uint64_t value,
                                                             Args... args) {
  std::string field;
  detail::make_range_header_core(field, value, args...);
  field.insert(0, "bytes=");
  return std::make_pair("Range", field);
}

// Request implementation
inline bool Request::has_header(const char *key) const {
  return detail::has_header(headers, key);
}

inline std::string Request::get_header_value(const char *key, size_t id) const {
  return detail::get_header_value(headers, key, id, "");
}

inline size_t Request::get_header_value_count(const char *key) const {
  auto r = headers.equal_range(key);
  return std::distance(r.first, r.second);
}

inline void Request::set_header(const char *key, const char *val) {
  headers.emplace(key, val);
}

inline bool Request::has_param(const char *key) const {
  return params.find(key) != params.end();
}

inline std::string Request::get_param_value(const char *key, size_t id) const {
  auto it = params.find(key);
  std::advance(it, id);
  if (it != params.end()) { return it->second; }
  return std::string();
}

inline size_t Request::get_param_value_count(const char *key) const {
  auto r = params.equal_range(key);
  return std::distance(r.first, r.second);
}

inline bool Request::has_file(const char *key) const {
  return files.find(key) != files.end();
}

inline MultipartFile Request::get_file_value(const char *key) const {
  auto it = files.find(key);
  if (it != files.end()) { return it->second; }
  return MultipartFile();
}

// Response implementation
inline bool Response::has_header(const char *key) const {
  return headers.find(key) != headers.end();
}

inline std::string Response::get_header_value(const char *key,
                                              size_t id) const {
  return detail::get_header_value(headers, key, id, "");
}

inline size_t Response::get_header_value_count(const char *key) const {
  auto r = headers.equal_range(key);
  return std::distance(r.first, r.second);
}

inline void Response::set_header(const char *key, const char *val) {
  headers.emplace(key, val);
}

inline void Response::set_redirect(const char *url) {
  set_header("Location", url);
  status = 302;
}

inline void Response::set_content(const char *s, size_t n,
                                  const char *content_type) {
  body.assign(s, n);
  set_header("Content-Type", content_type);
}

inline void Response::set_content(const std::string &s,
                                  const char *content_type) {
  body = s;
  set_header("Content-Type", content_type);
}

// Rstream implementation
template <typename... Args>
inline void Stream::write_format(const char *fmt, const Args &... args) {
  const auto bufsiz = 2048;
  char buf[bufsiz];

#if defined(_MSC_VER) && _MSC_VER < 1900
  auto n = _snprintf_s(buf, bufsiz, bufsiz - 1, fmt, args...);
#else
  auto n = snprintf(buf, bufsiz - 1, fmt, args...);
#endif
  if (n > 0) {
    if (n >= bufsiz - 1) {
      std::vector<char> glowable_buf(bufsiz);

      while (n >= static_cast<int>(glowable_buf.size() - 1)) {
        glowable_buf.resize(glowable_buf.size() * 2);
#if defined(_MSC_VER) && _MSC_VER < 1900
        n = _snprintf_s(&glowable_buf[0], glowable_buf.size(),
                        glowable_buf.size() - 1, fmt, args...);
#else
        n = snprintf(&glowable_buf[0], glowable_buf.size() - 1, fmt, args...);
#endif
      }
      write(&glowable_buf[0], n);
    } else {
      write(buf, n);
    }
  }
}

// Socket stream implementation
inline SocketStream::SocketStream(socket_t sock) : sock_(sock) {}

inline SocketStream::~SocketStream() {}

inline int SocketStream::read(char *ptr, size_t size) {
  return recv(sock_, ptr, static_cast<int>(size), 0);
}

inline int SocketStream::write(const char *ptr, size_t size) {
  return send(sock_, ptr, static_cast<int>(size), 0);
}

inline int SocketStream::write(const char *ptr) {
  return write(ptr, strlen(ptr));
}

inline std::string SocketStream::get_remote_addr() const {
  return detail::get_remote_addr(sock_);
}

// Buffer stream implementation
inline int BufferStream::read(char *ptr, size_t size) {
#if defined(_MSC_VER) && _MSC_VER < 1900
  return static_cast<int>(buffer._Copy_s(ptr, size, size));
#else
  return static_cast<int>(buffer.copy(ptr, size));
#endif
}

inline int BufferStream::write(const char *ptr, size_t size) {
  buffer.append(ptr, size);
  return static_cast<int>(size);
}

inline int BufferStream::write(const char *ptr) {
  size_t size = strlen(ptr);
  buffer.append(ptr, size);
  return static_cast<int>(size);
}

inline std::string BufferStream::get_remote_addr() const { return ""; }

inline const std::string &BufferStream::get_buffer() const { return buffer; }

// HTTP server implementation
inline Server::Server()
    : keep_alive_max_count_(CPPHTTPLIB_KEEPALIVE_MAX_COUNT),
      payload_max_length_(CPPHTTPLIB_PAYLOAD_MAX_LENGTH), is_running_(false),
      svr_sock_(INVALID_SOCKET), running_threads_(0) {
#ifndef _WIN32
  signal(SIGPIPE, SIG_IGN);
#endif
}

inline Server::~Server() {}

inline Server &Server::Get(const char *pattern, Handler handler) {
  get_handlers_.push_back(std::make_pair(std::regex(pattern), handler));
  return *this;
}

inline Server &Server::Post(const char *pattern, Handler handler) {
  post_handlers_.push_back(std::make_pair(std::regex(pattern), handler));
  return *this;
}

inline Server &Server::Put(const char *pattern, Handler handler) {
  put_handlers_.push_back(std::make_pair(std::regex(pattern), handler));
  return *this;
}

inline Server &Server::Patch(const char *pattern, Handler handler) {
  patch_handlers_.push_back(std::make_pair(std::regex(pattern), handler));
  return *this;
}

inline Server &Server::Delete(const char *pattern, Handler handler) {
  delete_handlers_.push_back(std::make_pair(std::regex(pattern), handler));
  return *this;
}

inline Server &Server::Options(const char *pattern, Handler handler) {
  options_handlers_.push_back(std::make_pair(std::regex(pattern), handler));
  return *this;
}

inline bool Server::set_base_dir(const char *path) {
  if (detail::is_dir(path)) {
    base_dir_ = path;
    return true;
  }
  return false;
}

inline void Server::set_error_handler(Handler handler) {
  error_handler_ = handler;
}

inline void Server::set_logger(Logger logger) { logger_ = logger; }

inline void Server::set_keep_alive_max_count(size_t count) {
  keep_alive_max_count_ = count;
}

inline void Server::set_payload_max_length(uint64_t length) {
  payload_max_length_ = length;
}

inline int Server::bind_to_any_port(const char *host, int socket_flags) {
  return bind_internal(host, 0, socket_flags);
}

inline bool Server::listen_after_bind() { return listen_internal(); }

inline bool Server::listen(const char *host, int port, int socket_flags) {
  if (bind_internal(host, port, socket_flags) < 0) return false;
  return listen_internal();
}

inline bool Server::is_running() const { return is_running_; }

inline void Server::stop() {
  if (is_running_) {
    assert(svr_sock_ != INVALID_SOCKET);
    auto sock = svr_sock_;
    svr_sock_ = INVALID_SOCKET;
    detail::shutdown_socket(sock);
    detail::close_socket(sock);
  }
}

inline bool Server::parse_request_line(const char *s, Request &req) {
  static std::regex re("(GET|HEAD|POST|PUT|PATCH|DELETE|OPTIONS) "
                       "(([^?]+)(?:\\?(.+?))?) (HTTP/1\\.[01])\r\n");

  std::cmatch m;
  if (std::regex_match(s, m, re)) {
    req.version = std::string(m[5]);
    req.method = std::string(m[1]);
    req.target = std::string(m[2]);
    req.path = detail::decode_url(m[3]);

    // Parse query text
    auto len = std::distance(m[4].first, m[4].second);
    if (len > 0) { detail::parse_query_text(m[4], req.params); }

    return true;
  }

  return false;
}

inline void Server::write_response(Stream &strm, bool last_connection,
                                   const Request &req, Response &res) {
  assert(res.status != -1);

  if (400 <= res.status && error_handler_) { error_handler_(req, res); }

  // Response line
  strm.write_format("HTTP/1.1 %d %s\r\n", res.status,
                    detail::status_message(res.status));

  // Headers
  if (last_connection || req.get_header_value("Connection") == "close") {
    res.set_header("Connection", "close");
  }

  if (!last_connection && req.get_header_value("Connection") == "Keep-Alive") {
    res.set_header("Connection", "Keep-Alive");
  }

  if (res.body.empty()) {
    if (!res.has_header("Content-Length")) {
      if (res.streamcb) {
        // Streamed response
        res.set_header("Transfer-Encoding", "chunked");
      } else {
        res.set_header("Content-Length", "0");
      }
    }
  } else {
#ifdef CPPHTTPLIB_ZLIB_SUPPORT
    // TODO: 'Accpet-Encoding' has gzip, not gzip;q=0
    const auto &encodings = req.get_header_value("Accept-Encoding");
    if (encodings.find("gzip") != std::string::npos &&
        detail::can_compress(res.get_header_value("Content-Type"))) {
      detail::compress(res.body);
      res.set_header("Content-Encoding", "gzip");
    }
#endif

    if (!res.has_header("Content-Type")) {
      res.set_header("Content-Type", "text/plain");
    }

    auto length = std::to_string(res.body.size());
    res.set_header("Content-Length", length.c_str());
  }

  detail::write_headers(strm, res);

  // Body
  if (req.method != "HEAD") {
    if (!res.body.empty()) {
      strm.write(res.body.c_str(), res.body.size());
    } else if (res.streamcb) {
      bool chunked_response = !res.has_header("Content-Length");
      uint64_t offset = 0;
      bool data_available = true;
      while (data_available) {
        std::string chunk = res.streamcb(offset);
        offset += chunk.size();
        data_available = !chunk.empty();
        // Emit chunked response header and footer for each chunk
        if (chunked_response)
          chunk = detail::from_i_to_hex(chunk.size()) + "\r\n" + chunk + "\r\n";
        if (strm.write(chunk.c_str(), chunk.size()) < 0) break; // Stop on error
      }
    }
  }

  // Log
  if (logger_) { logger_(req, res); }
}

inline bool Server::handle_file_request(Request &req, Response &res) {
  if (!base_dir_.empty() && detail::is_valid_path(req.path)) {
    std::string path = base_dir_ + req.path;

    if (!path.empty() && path.back() == '/') { path += "index.html"; }

    if (detail::is_file(path)) {
      detail::read_file(path, res.body);
      auto type = detail::find_content_type(path);
      if (type) { res.set_header("Content-Type", type); }
      res.status = 200;
      return true;
    }
  }

  return false;
}

inline socket_t Server::create_server_socket(const char *host, int port,
                                             int socket_flags) const {
  return detail::create_socket(
      host, port,
      [](socket_t sock, struct addrinfo &ai) -> bool {
        if (::bind(sock, ai.ai_addr, static_cast<int>(ai.ai_addrlen))) {
          return false;
        }
        if (::listen(sock, 5)) { // Listen through 5 channels
          return false;
        }
        return true;
      },
      socket_flags);
}

inline int Server::bind_internal(const char *host, int port, int socket_flags) {
  if (!is_valid()) { return -1; }

  svr_sock_ = create_server_socket(host, port, socket_flags);
  if (svr_sock_ == INVALID_SOCKET) { return -1; }

  if (port == 0) {
    struct sockaddr_storage address;
    socklen_t len = sizeof(address);
    if (getsockname(svr_sock_, reinterpret_cast<struct sockaddr *>(&address),
                    &len) == -1) {
      return -1;
    }
    if (address.ss_family == AF_INET) {
      return ntohs(reinterpret_cast<struct sockaddr_in *>(&address)->sin_port);
    } else if (address.ss_family == AF_INET6) {
      return ntohs(
          reinterpret_cast<struct sockaddr_in6 *>(&address)->sin6_port);
    } else {
      return -1;
    }
  } else {
    return port;
  }
}

inline bool Server::listen_internal() {
  auto ret = true;

  is_running_ = true;

  for (;;) {
    auto val = detail::select_read(svr_sock_, 0, 100000);

    if (val == 0) { // Timeout
      if (svr_sock_ == INVALID_SOCKET) {
        // The server socket was closed by 'stop' method.
        break;
      }
      continue;
    }

    socket_t sock = accept(svr_sock_, NULL, NULL);

    if (sock == INVALID_SOCKET) {
      if (svr_sock_ != INVALID_SOCKET) {
        detail::close_socket(svr_sock_);
        ret = false;
      } else {
        ; // The server socket was closed by user.
      }
      break;
    }

    // TODO: Use thread pool...
    std::thread([=]() {
      {
        std::lock_guard<std::mutex> guard(running_threads_mutex_);
        running_threads_++;
      }

      read_and_close_socket(sock);

      {
        std::lock_guard<std::mutex> guard(running_threads_mutex_);
        running_threads_--;
      }
    }).detach();
  }

  // TODO: Use thread pool...
  for (;;) {
    std::this_thread::sleep_for(std::chrono::milliseconds(10));
    std::lock_guard<std::mutex> guard(running_threads_mutex_);
    if (!running_threads_) { break; }
  }

  is_running_ = false;

  return ret;
}

inline bool Server::routing(Request &req, Response &res) {
  if (req.method == "GET" && handle_file_request(req, res)) { return true; }

  if (req.method == "GET" || req.method == "HEAD") {
    return dispatch_request(req, res, get_handlers_);
  } else if (req.method == "POST") {
    return dispatch_request(req, res, post_handlers_);
  } else if (req.method == "PUT") {
    return dispatch_request(req, res, put_handlers_);
  } else if (req.method == "PATCH") {
    return dispatch_request(req, res, patch_handlers_);
  } else if (req.method == "DELETE") {
    return dispatch_request(req, res, delete_handlers_);
  } else if (req.method == "OPTIONS") {
    return dispatch_request(req, res, options_handlers_);
  }
  return false;
}

inline bool Server::dispatch_request(Request &req, Response &res,
                                     Handlers &handlers) {
  for (const auto &x : handlers) {
    const auto &pattern = x.first;
    const auto &handler = x.second;

    if (std::regex_match(req.path, req.matches, pattern)) {
      handler(req, res);
      return true;
    }
  }
  return false;
}

inline bool Server::process_request(Stream &strm, bool last_connection,
                                    bool &connection_close) {
  const auto bufsiz = 2048;
  char buf[bufsiz];

  detail::stream_line_reader reader(strm, buf, bufsiz);

  // Connection has been closed on client
  if (!reader.getline()) { return false; }

  Request req;
  Response res;

  res.version = "HTTP/1.1";

  // Check if the request URI doesn't exceed the limit
  if (reader.size() > CPPHTTPLIB_REQUEST_URI_MAX_LENGTH) {
    res.status = 414;
    write_response(strm, last_connection, req, res);
    return true;
  }

  // Request line and headers
  if (!parse_request_line(reader.ptr(), req) ||
      !detail::read_headers(strm, req.headers)) {
    res.status = 400;
    write_response(strm, last_connection, req, res);
    return true;
  }

  if (req.get_header_value("Connection") == "close") {
    connection_close = true;
  }

  req.set_header("REMOTE_ADDR", strm.get_remote_addr().c_str());

  // Body
  if (req.method == "POST" || req.method == "PUT" || req.method == "PATCH") {
    bool exceed_payload_max_length = false;
    if (!detail::read_content(strm, req, payload_max_length_,
                              exceed_payload_max_length)) {
      res.status = exceed_payload_max_length ? 413 : 400;
      write_response(strm, last_connection, req, res);
      return !exceed_payload_max_length;
    }

    const auto &content_type = req.get_header_value("Content-Type");

    if (req.get_header_value("Content-Encoding") == "gzip") {
#ifdef CPPHTTPLIB_ZLIB_SUPPORT
      detail::decompress(req.body);
#else
      res.status = 415;
      write_response(strm, last_connection, req, res);
      return true;
#endif
    }

    if (!content_type.find("application/x-www-form-urlencoded")) {
      detail::parse_query_text(req.body, req.params);
    } else if (!content_type.find("multipart/form-data")) {
      std::string boundary;
      if (!detail::parse_multipart_boundary(content_type, boundary) ||
          !detail::parse_multipart_formdata(boundary, req.body, req.files)) {
        res.status = 400;
        write_response(strm, last_connection, req, res);
        return true;
      }
    }
  }

  if (routing(req, res)) {
    if (res.status == -1) { res.status = 200; }
  } else {
    res.status = 404;
  }

  write_response(strm, last_connection, req, res);
  return true;
}

inline bool Server::is_valid() const { return true; }

inline bool Server::read_and_close_socket(socket_t sock) {
  return detail::read_and_close_socket(
      sock, keep_alive_max_count_,
      [this](Stream &strm, bool last_connection, bool &connection_close) {
        return process_request(strm, last_connection, connection_close);
      });
}

// HTTP client implementation
inline Client::Client(const char *host, int port, time_t timeout_sec)
    : host_(host), port_(port), timeout_sec_(timeout_sec),
      host_and_port_(host_ + ":" + std::to_string(port_)) {}

inline Client::~Client() {}

inline bool Client::is_valid() const { return true; }

inline socket_t Client::create_client_socket() const {
  return detail::create_socket(
      host_.c_str(), port_, [=](socket_t sock, struct addrinfo &ai) -> bool {
        detail::set_nonblocking(sock, true);

        auto ret = connect(sock, ai.ai_addr, static_cast<int>(ai.ai_addrlen));
        if (ret < 0) {
          if (detail::is_connection_error() ||
              !detail::wait_until_socket_is_ready(sock, timeout_sec_, 0)) {
            detail::close_socket(sock);
            return false;
          }
        }

        detail::set_nonblocking(sock, false);
        return true;
      });
}

inline bool Client::read_response_line(Stream &strm, Response &res) {
  const auto bufsiz = 2048;
  char buf[bufsiz];

  detail::stream_line_reader reader(strm, buf, bufsiz);

  if (!reader.getline()) { return false; }

  const static std::regex re("(HTTP/1\\.[01]) (\\d+?) .*\r\n");

  std::cmatch m;
  if (std::regex_match(reader.ptr(), m, re)) {
    res.version = std::string(m[1]);
    res.status = std::stoi(std::string(m[2]));
  }

  return true;
}

inline bool Client::send(Request &req, Response &res) {
  if (req.path.empty()) { return false; }

  auto sock = create_client_socket();
  if (sock == INVALID_SOCKET) { return false; }

  return read_and_close_socket(sock, req, res);
}

inline void Client::write_request(Stream &strm, Request &req) {
  BufferStream bstrm;

  // Request line
  auto path = detail::encode_url(req.path);

  bstrm.write_format("%s %s HTTP/1.1\r\n", req.method.c_str(), path.c_str());

  // Headers
  if (!req.has_header("Host")) {
    if (is_ssl()) {
      if (port_ == 443) {
        req.set_header("Host", host_.c_str());
      } else {
        req.set_header("Host", host_and_port_.c_str());
      }
    } else {
      if (port_ == 80) {
        req.set_header("Host", host_.c_str());
      } else {
        req.set_header("Host", host_and_port_.c_str());
      }
    }
  }

  if (!req.has_header("Accept")) { req.set_header("Accept", "*/*"); }

  if (!req.has_header("User-Agent")) {
    req.set_header("User-Agent", "cpp-httplib/0.2");
  }

  // TODO: Support KeepAlive connection
  // if (!req.has_header("Connection")) {
  req.set_header("Connection", "close");
  // }

  if (req.body.empty()) {
    if (req.method == "POST" || req.method == "PUT" || req.method == "PATCH") {
      req.set_header("Content-Length", "0");
    }
  } else {
    if (!req.has_header("Content-Type")) {
      req.set_header("Content-Type", "text/plain");
    }

    if (!req.has_header("Content-Length")) {
      auto length = std::to_string(req.body.size());
      req.set_header("Content-Length", length.c_str());
    }
  }

  detail::write_headers(bstrm, req);

  // Body
  if (!req.body.empty()) { bstrm.write(req.body.c_str(), req.body.size()); }

  // Flush buffer
  auto &data = bstrm.get_buffer();
  strm.write(data.data(), data.size());
}

inline bool Client::process_request(Stream &strm, Request &req, Response &res,
                                    bool &connection_close) {
  // Send request
  write_request(strm, req);

  // Receive response and headers
  if (!read_response_line(strm, res) ||
      !detail::read_headers(strm, res.headers)) {
    return false;
  }

  if (res.get_header_value("Connection") == "close" ||
      res.version == "HTTP/1.0") {
    connection_close = true;
  }

  // Body
  if (req.method != "HEAD") {
    bool exceed_payload_max_length = false;
    if (!detail::read_content(strm, res, std::numeric_limits<uint64_t>::max(),
                              exceed_payload_max_length, req.progress)) {
      return false;
    }

    if (res.get_header_value("Content-Encoding") == "gzip") {
#ifdef CPPHTTPLIB_ZLIB_SUPPORT
      detail::decompress(res.body);
#else
      return false;
#endif
    }
  }

  return true;
}

inline bool Client::read_and_close_socket(socket_t sock, Request &req,
                                          Response &res) {
  return detail::read_and_close_socket(
      sock, 0,
      [&](Stream &strm, bool /*last_connection*/, bool &connection_close) {
        return process_request(strm, req, res, connection_close);
      });
}

inline bool Client::is_ssl() const { return false; }

inline std::shared_ptr<Response> Client::Get(const char *path,
                                             Progress progress) {
  return Get(path, Headers(), progress);
}

inline std::shared_ptr<Response>
Client::Get(const char *path, const Headers &headers, Progress progress) {
  Request req;
  req.method = "GET";
  req.path = path;
  req.headers = headers;
  req.progress = progress;

  auto res = std::make_shared<Response>();

  return send(req, *res) ? res : nullptr;
}

inline std::shared_ptr<Response> Client::Head(const char *path) {
  return Head(path, Headers());
}

inline std::shared_ptr<Response> Client::Head(const char *path,
                                              const Headers &headers) {
  Request req;
  req.method = "HEAD";
  req.headers = headers;
  req.path = path;

  auto res = std::make_shared<Response>();

  return send(req, *res) ? res : nullptr;
}

inline std::shared_ptr<Response> Client::Post(const char *path,
                                              const std::string &body,
                                              const char *content_type) {
  return Post(path, Headers(), body, content_type);
}

inline std::shared_ptr<Response> Client::Post(const char *path,
                                              const Headers &headers,
                                              const std::string &body,
                                              const char *content_type) {
  Request req;
  req.method = "POST";
  req.headers = headers;
  req.path = path;

  req.headers.emplace("Content-Type", content_type);
  req.body = body;

  auto res = std::make_shared<Response>();

  return send(req, *res) ? res : nullptr;
}

inline std::shared_ptr<Response> Client::Post(const char *path,
                                              const Params &params) {
  return Post(path, Headers(), params);
}

inline std::shared_ptr<Response>
Client::Post(const char *path, const Headers &headers, const Params &params) {
  std::string query;
  for (auto it = params.begin(); it != params.end(); ++it) {
    if (it != params.begin()) { query += "&"; }
    query += it->first;
    query += "=";
    query += it->second;
  }

  return Post(path, headers, query, "application/x-www-form-urlencoded");
}

inline std::shared_ptr<Response> Client::Put(const char *path,
                                             const std::string &body,
                                             const char *content_type) {
  return Put(path, Headers(), body, content_type);
}

inline std::shared_ptr<Response> Client::Put(const char *path,
                                             const Headers &headers,
                                             const std::string &body,
                                             const char *content_type) {
  Request req;
  req.method = "PUT";
  req.headers = headers;
  req.path = path;

  req.headers.emplace("Content-Type", content_type);
  req.body = body;

  auto res = std::make_shared<Response>();

  return send(req, *res) ? res : nullptr;
}

inline std::shared_ptr<Response> Client::Patch(const char *path,
                                               const std::string &body,
                                               const char *content_type) {
  return Patch(path, Headers(), body, content_type);
}

inline std::shared_ptr<Response> Client::Patch(const char *path,
                                               const Headers &headers,
                                               const std::string &body,
                                               const char *content_type) {
  Request req;
  req.method = "PATCH";
  req.headers = headers;
  req.path = path;

  req.headers.emplace("Content-Type", content_type);
  req.body = body;

  auto res = std::make_shared<Response>();

  return send(req, *res) ? res : nullptr;
}

inline std::shared_ptr<Response> Client::Delete(const char *path) {
  return Delete(path, Headers());
}

inline std::shared_ptr<Response> Client::Delete(const char *path,
                                                const Headers &headers) {
  Request req;
  req.method = "DELETE";
  req.path = path;
  req.headers = headers;

  auto res = std::make_shared<Response>();

  return send(req, *res) ? res : nullptr;
}

inline std::shared_ptr<Response> Client::Options(const char *path) {
  return Options(path, Headers());
}

inline std::shared_ptr<Response> Client::Options(const char *path,
                                                 const Headers &headers) {
  Request req;
  req.method = "OPTIONS";
  req.path = path;
  req.headers = headers;

  auto res = std::make_shared<Response>();

  return send(req, *res) ? res : nullptr;
}

/*
 * SSL Implementation
 */
#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
namespace detail {

template <typename U, typename V, typename T>
inline bool
read_and_close_socket_ssl(socket_t sock, size_t keep_alive_max_count,
                          // TODO: OpenSSL 1.0.2 occasionally crashes...
                          // The upcoming 1.1.0 is going to be thread safe.
                          SSL_CTX *ctx, std::mutex &ctx_mutex,
                          U SSL_connect_or_accept, V setup, T callback) {
  SSL *ssl = nullptr;
  {
    std::lock_guard<std::mutex> guard(ctx_mutex);

    ssl = SSL_new(ctx);
    if (!ssl) { return false; }
  }

  auto bio = BIO_new_socket(sock, BIO_NOCLOSE);
  SSL_set_bio(ssl, bio, bio);

  setup(ssl);

  SSL_connect_or_accept(ssl);

  bool ret = false;

  if (keep_alive_max_count > 0) {
    auto count = keep_alive_max_count;
    while (count > 0 &&
           detail::select_read(sock, CPPHTTPLIB_KEEPALIVE_TIMEOUT_SECOND,
                               CPPHTTPLIB_KEEPALIVE_TIMEOUT_USECOND) > 0) {
      SSLSocketStream strm(sock, ssl);
      auto last_connection = count == 1;
      auto connection_close = false;

      ret = callback(strm, last_connection, connection_close);
      if (!ret || connection_close) { break; }

      count--;
    }
  } else {
    SSLSocketStream strm(sock, ssl);
    auto dummy_connection_close = false;
    ret = callback(strm, true, dummy_connection_close);
  }

  SSL_shutdown(ssl);

  {
    std::lock_guard<std::mutex> guard(ctx_mutex);
    SSL_free(ssl);
  }

  close_socket(sock);

  return ret;
}

class SSLInit {
public:
  SSLInit() {
    SSL_load_error_strings();
    SSL_library_init();
  }

  ~SSLInit() { ERR_free_strings(); }
};

static SSLInit sslinit_;

} // namespace detail

// SSL socket stream implementation
inline SSLSocketStream::SSLSocketStream(socket_t sock, SSL *ssl)
    : sock_(sock), ssl_(ssl) {}

inline SSLSocketStream::~SSLSocketStream() {}

inline int SSLSocketStream::read(char *ptr, size_t size) {
  return SSL_read(ssl_, ptr, size);
}

inline int SSLSocketStream::write(const char *ptr, size_t size) {
  return SSL_write(ssl_, ptr, size);
}

inline int SSLSocketStream::write(const char *ptr) {
  return write(ptr, strlen(ptr));
}

inline std::string SSLSocketStream::get_remote_addr() const {
  return detail::get_remote_addr(sock_);
}

// SSL HTTP server implementation
inline SSLServer::SSLServer(const char *cert_path,
                            const char *private_key_path) {
  ctx_ = SSL_CTX_new(SSLv23_server_method());

  if (ctx_) {
    SSL_CTX_set_options(ctx_,
                        SSL_OP_ALL | SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3 |
                            SSL_OP_NO_COMPRESSION |
                            SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION);

    // auto ecdh = EC_KEY_new_by_curve_name(NID_X9_62_prime256v1);
    // SSL_CTX_set_tmp_ecdh(ctx_, ecdh);
    // EC_KEY_free(ecdh);

    if (SSL_CTX_use_certificate_chain_file(ctx_, cert_path) != 1 ||
        SSL_CTX_use_PrivateKey_file(ctx_, private_key_path, SSL_FILETYPE_PEM) !=
            1) {
      SSL_CTX_free(ctx_);
      ctx_ = nullptr;
    }
  }
}

inline SSLServer::~SSLServer() {
  if (ctx_) { SSL_CTX_free(ctx_); }
}

inline bool SSLServer::is_valid() const { return ctx_; }

inline bool SSLServer::read_and_close_socket(socket_t sock) {
  return detail::read_and_close_socket_ssl(
      sock, keep_alive_max_count_, ctx_, ctx_mutex_, SSL_accept,
      [](SSL * /*ssl*/) {},
      [this](Stream &strm, bool last_connection, bool &connection_close) {
        return process_request(strm, last_connection, connection_close);
      });
}

// SSL HTTP client implementation
inline SSLClient::SSLClient(const char *host, int port, time_t timeout_sec)
    : Client(host, port, timeout_sec) {
  ctx_ = SSL_CTX_new(SSLv23_client_method());
}

inline SSLClient::~SSLClient() {
  if (ctx_) { SSL_CTX_free(ctx_); }
}

inline bool SSLClient::is_valid() const { return ctx_; }

inline bool SSLClient::read_and_close_socket(socket_t sock, Request &req,
                                             Response &res) {
  return is_valid() &&
         detail::read_and_close_socket_ssl(
             sock, 0, ctx_, ctx_mutex_, SSL_connect,
             [&](SSL *ssl) { SSL_set_tlsext_host_name(ssl, host_.c_str()); },
             [&](Stream &strm, bool /*last_connection*/,
                 bool &connection_close) {
               return process_request(strm, req, res, connection_close);
             });
}

inline bool SSLClient::is_ssl() const { return true; }
#endif

} // namespace httplib

#endif // CPPHTTPLIB_HTTPLIB_H

// vim: et ts=4 sw=4 cin cino={1s ff=unix